content: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2009, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
   * in the United States and other countries.]
   *
   * -------------------------
   * AbstractMouseHandler.java
   * -------------------------
   * (C) Copyright 2009, by Object Refinery Limited.
   *
   * Original Author:  David Gilbert (for Object Refinery Limited);
   * Contributor(s):   -;
   *
   * Changes:
   * --------
   * 18-Jun-2009 : Version 1 (DG);
   *
   */
  
  package org.jfree.chart.panel;
  
  import java.awt.event.MouseEvent;
  import java.awt.event.MouseListener;
  import java.awt.event.MouseMotionListener;
  import java.io.Serializable;
  
  import org.jfree.chart.ChartPanel;
  
  /**
   * A handler for mouse events in a {@link ChartPanel}.  A handler can be
   * assigned a modifier and installed on the panel to be invoked by the user.
   */
  public abstract class AbstractMouseHandler implements MouseListener,
          MouseMotionListener, Serializable {
  
      /** a generated serial id. */
      private static final long serialVersionUID = -2717376020576340947L;
  
      /** The modifier used to invoke this handler. */
      private int modifier;
  
      /**
       * Default constructor.
       */
      public AbstractMouseHandler() {
          this.modifier = 0;
      }
      
      /**
       * Constructing with modifier.
       */
      public AbstractMouseHandler(int modifier) {
          this.modifier = modifier;
      }
  
      /**
       * Returns the modifier for this handler.
       *
       * @return The modifier.
       */
      public int getModifier() {
          return this.modifier;
      }
  
      /**
       * Sets the modifier for this handler.
       *
       * @param modifier  the modifier.
       */
      public void setModifier(int modifier) {
          this.modifier = modifier;
      }
  
      /**
       * Handle a mouse pressed event.  This implementation does nothing -
       * subclasses should override if necessary.
       *
       * @param e  the mouse event.
       */
      public void mousePressed(MouseEvent e) {
          // override to do something
      }
  
      /**
       * Handle a mouse released event.  This implementation does nothing -
       * subclasses should override if necessary.
       *
       * @param e  the mouse event.
       */
      public void mouseReleased(MouseEvent e) {
          // override if you need this method to do something
      }
  
      /**
       * Handle a mouse clicked event.  This implementation does nothing -
       * subclasses should override if necessary.
       *
       * @param e  the mouse event.
       */
      public void mouseClicked(MouseEvent e) {
          // override if you need this method to do something
      }
  
      /**
       * Handle a mouse entered event.  This implementation does nothing -
       * subclasses should override if necessary.
       *
       * @param e  the mouse event.
       */
      public void mouseEntered(MouseEvent e) {
          // override if you need this method to do something
      }
  
      /**
       * Handle a mouse moved event.  This implementation does nothing -
       * subclasses should override if necessary.
       *
       * @param e  the mouse event.
       */
      public void mouseMoved(MouseEvent e) {
          // override if you need this method to do something
      }
  
      /**
       * Handle a mouse exited event.  This implementation does nothing -
       * subclasses should override if necessary.
       *
       * @param e  the mouse event.
       */
      public void mouseExited(MouseEvent e) {
          // override if you need this method to do something
      }
  
      /**
       * Handle a mouse dragged event.  This implementation does nothing -
       * subclasses should override if necessary.
       *
       * @param e  the mouse event.
       */
      public void mouseDragged(MouseEvent e) {
          // override if you need this method to do something
      }
  
      /**
       * A mouse handler is either an live handler or an auxiliary handler. While
       * there can be only one active live handler at a time many auxiliary 
       * handlers can be used together.  E.g. rectangle zooming and rectangle 
       * selection should be implemented as live handlers because they both draw 
       * on the panel and shouldn't be combined. In contrast a click selection 
       * does not interfere with e.g. a double click selection both handlers can 
       * be active at the same time. 
       * 
       * @return true if this is a live handler
       */
      public abstract boolean isLiveHandler();
  }
  